Antibacterial ceramic material and method for its production

Abstract

The application provides an antibacterial ceramic material and a preparation method thereof, and relates to the technical field of antibacterial materials.The antibacterial ceramic material comprises a ceramic inner layer and an antibacterial outer layer; the antibacterial outer layer is coated on the outer surface of the ceramic inner layer, and the antibacterial outer layer contains an antibacterial agent; the antibacterial agent is inorganic antibacterial components loaded on an inorganic carrier, and the inorganic carrier comprises an inorganic calcium compound.The antibacterial ceramic material has the characteristics of good antibacterial property and long-lasting antibacterial property.

Description

Technical Field

[0001] This invention belongs to the field of antibacterial materials technology, and relates to an antibacterial ceramic material and its preparation method. Background Technology

[0002] Ceramics are a traditional building material, widely used in various fields due to their high strength, wear resistance, and corrosion resistance. However, ceramic materials also have some drawbacks, such as their susceptibility to bacterial growth, which can affect their performance and lifespan. One solution is to coat the ceramic surface with an antibacterial glaze or ceramic layer. For example, inorganic antibacterial agents (nano-silver, nano-zinc oxide, etc.) can be added to the glaze or ceramic matrix, mixed evenly, coated onto the ceramic surface, and then sintered to form an antibacterial glaze or antibacterial ceramic layer.

[0003] However, the antibacterial properties of the antibacterial ceramics obtained by the above methods are still insufficient, mainly in the following two aspects: (1) poor antibacterial rate; (2) short antibacterial duration.

[0004] Therefore, the above problems urgently need to be solved. Summary of the Invention

[0005] For inorganic antibacterial agents in glaze or ceramic layers to function, two steps are required: the first step is for the inorganic antibacterial agent to detach from the carrier, and the second step is for the detached inorganic antibacterial agent to penetrate the surface glaze or ceramic layer and be released into the environment. The inventors have found that the main reasons for the poor antibacterial performance of existing antibacterial ceramics are as follows: (1) Inorganic antibacterial agents are generally first loaded onto the carrier. If the binding force between the inorganic antibacterial agent and the carrier is too strong, the inorganic antibacterial agent cannot effectively detach from the carrier, or if the binding force between the inorganic antibacterial agent and the carrier is too weak, the inorganic antibacterial agent will quickly detach completely from the carrier, resulting in poor antibacterial persistence; (2) The sintered glaze or ceramic layer is relatively dense. Even if the inorganic antibacterial agent can detach from the carrier, it cannot penetrate the dense glaze or ceramic layer and be released into the environment, resulting in insufficient antibacterial performance. Surprisingly, it was found that using inorganic calcium compounds as a carrier for antibacterial components can solve the above problems. Based on this, the present invention provides an antibacterial ceramic material and its preparation method.

[0006] The technical solution of the present invention is as follows:

[0007] An antibacterial ceramic material, comprising ceramic and an antibacterial outer layer;

[0008] The antibacterial outer layer covers the outer surface of the ceramic, and the antibacterial outer layer contains an antibacterial agent;

[0009] The antibacterial agent is an inorganic antibacterial component loaded on an inorganic carrier;

[0010] The inorganic carrier contains an inorganic calcium compound.

[0011] Preferably, the antibacterial agent accounts for no more than 20% and no less than 3% of the weight of the antibacterial outer layer.

[0012] Preferably, the inorganic antibacterial component is selected from one or a combination of two or more of silver antibacterial agents and nano zinc oxide.

[0013] More preferably, the silver antibacterial agent is selected from one or a combination of two or more of the following: silver nanoparticles, silver nitrate, silver nano oxide particles, silver sulfate, silver phosphate, and silver ammonium phosphate.

[0014] More preferably, the inorganic antibacterial component is composed of silver antibacterial agent and nano zinc oxide in a weight ratio of 1:20-1:1.

[0015] Preferably, the weight ratio of the inorganic antibacterial component to the inorganic carrier is 3-20:80-97.

[0016] Preferably, the inorganic calcium compound is selected from one or a combination of two or more of calcium oxide, calcium carbonate, calcium hydroxide, calcium sulfate, calcium chloride, dicalcium hydrogen phosphate, and calcium phosphate.

[0017] Preferably, the inorganic carrier further comprises a second carrier, wherein the weight percentage of the second carrier in the inorganic carrier is not higher than 30%, and the second carrier is selected from one or a combination of two or more of zirconium phosphate, silica, zeolite, attapulgite, montmorillonite, bentonite and kaolin.

[0018] Preferably, the antibacterial agent is prepared by mixing and dispersing the inorganic antibacterial component and the inorganic carrier.

[0019] A method for preparing the antibacterial ceramic material according to any of the above embodiments includes the following steps:

[0020] S1. Add the antibacterial agent to the glaze base material or ceramic base material, mix evenly, and obtain a premix;

[0021] S2. The premixed material described in step S1 is coated onto the ceramic surface and sintered to obtain the antibacterial ceramic material.

[0022] The beneficial effects of this invention are:

[0023] (1) The present invention uses inorganic calcium compounds as carriers for inorganic antibacterial components, which has two functions: 1) The binding force between inorganic calcium compounds and inorganic antibacterial components is moderate, and the inorganic antibacterial components can slowly and continuously detach from the inorganic calcium compounds and be released; 2) When antibacterial agents are added to glaze base materials or ceramic base materials and sintered to prepare antibacterial glaze layers or antibacterial ceramic layers, tiny openings or more micropores can be formed in the glaze layer or ceramic layer, which is conducive to the continuous release of antibacterial components detached from the carrier into the environment through the openings.

[0024] (2) The antibacterial ceramic material of the present invention has a long-lasting antibacterial performance and can continuously release inorganic antibacterial components for 6 months or more, thus providing good antibacterial performance continuously. Detailed Implementation

[0025] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0026] To address the problems of poor antibacterial properties of existing ceramics, poor antibacterial properties of antibacterial glazes, and inability to continuously provide antibacterial properties, this invention provides an antibacterial ceramic material composed of ceramic and an antibacterial outer layer.

[0027] An antibacterial outer layer is coated on the outer surface of the ceramic, and the antibacterial outer layer contains an antibacterial agent;

[0028] Antibacterial agents are inorganic antibacterial components loaded on an inorganic carrier;

[0029] The inorganic carrier contains inorganic calcium compounds.

[0030] The aforementioned antibacterial outer layer can be an antibacterial ceramic layer or an antibacterial glaze layer; that is, the main material of the antibacterial outer layer is ceramic or glaze.

[0031] In this invention, the antibacterial outer layer contains an antibacterial agent, which is an inorganic antibacterial component loaded on an inorganic carrier. The inorganic carrier can improve the dispersibility of the inorganic antibacterial component, and the inorganic carrier contains at least an inorganic calcium compound, which can have the following two effects: (1) the binding force between the inorganic calcium compound and the inorganic antibacterial component is moderate, and the inorganic antibacterial component can gradually detach from the surface of the inorganic calcium compound; (2) by using an inorganic calcium compound, micropores or more micropores can be formed in the antibacterial outer layer during the sintering process of the antibacterial outer layer, which helps the detached inorganic antibacterial component to penetrate the antibacterial outer layer and be released into the environment, thereby playing an antibacterial role.

[0032] In a preferred embodiment of the present invention, the weight percentage of the antibacterial agent in the antibacterial outer layer is not higher than 20% and not lower than 3%. If the weight percentage of the antibacterial agent in the antibacterial outer layer is too high, it will lead to insufficient performance of the antibacterial outer layer, such as insufficient adhesion to the ceramic inner layer, or too many micropores, affecting the quality of the antibacterial outer layer and causing the antibacterial components to be released too quickly. If the weight percentage of the antibacterial agent in the antibacterial outer layer is insufficient, the antibacterial performance of the antibacterial outer layer will be insufficient. For example, the weight percentage of the antibacterial agent in the antibacterial outer layer can be any value from 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc., but is not limited to those listed above. Alternatively, further, the weight percentage of the antibacterial agent in the antibacterial outer layer can be 5%-18%.

[0033] In a preferred embodiment of the present invention, the inorganic antibacterial component is selected from one or a combination of two or more of silver antibacterial agents and nano-zinc oxide. In this invention, the inorganic antibacterial component can be obtained directly from the market or prepared according to existing technology; the average particle size of the inorganic antibacterial component can be 10nm-100nm. Silver antibacterial agents and nano-zinc oxide are both commonly used inorganic antibacterial components with good antibacterial properties. Further, the silver antibacterial agent can be selected from one or a combination of two or more of nano-silver particles, silver nitrate, nano-silver oxide particles, silver sulfate, silver phosphate, and silver ammonium phosphate.

[0034] In a more preferred embodiment of the present invention, the inorganic antibacterial component is composed of a silver antibacterial agent and nano-zinc oxide in a weight ratio of 1:20 to 1:1. The inorganic antibacterial component, composed of a silver antibacterial agent and nano-zinc oxide, can synergistically exert the effects of the two antibacterial agents, further improving the antibacterial performance. For example, the weight ratio of the silver antibacterial agent to nano-zinc oxide can be any value from 1:20, 1:19, 1:18, 1:17, 1:16, 1:15, 1:14, 1:13, 1:12, 1:11, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, etc., but is not limited to those listed above. More preferably, the inorganic antibacterial component is composed of a silver antibacterial agent and nano-zinc oxide in a weight ratio of 1:15 to 1:3.

[0035] In a preferred embodiment of the present invention, the weight ratio of the inorganic antibacterial component to the inorganic carrier is 3-20:80-97. In this invention, the average particle size of the inorganic carrier can be 200 nm-5 μm. A weight ratio of inorganic antibacterial component to inorganic carrier within the above range can achieve a better loading effect. If there is too little inorganic carrier and too much inorganic antibacterial component, some of the inorganic antibacterial component will be unevenly dispersed and aggregated. If there is too much inorganic carrier and too little inorganic antibacterial component, the utilization rate of the inorganic carrier will be insufficient, and the antibacterial agent will be insufficient, affecting the antibacterial performance. For example, the weight ratio of the inorganic antibacterial component to the inorganic carrier can be any value from 3:97, 4:96, 5:95, 6:94, 7:93, 8:92, 9:91, 10:90, 11:89, 12:88, 13:87, 14:86, 15:85, 16:84, 17:83, 18:82, 19:81, 20:80, etc., but is not limited to those listed above. Alternatively, the weight ratio of the inorganic antibacterial component to the inorganic carrier can be 5-17:83-95.

[0036] In a preferred embodiment of the present invention, the inorganic calcium compound is selected from one or a combination of two or more of calcium oxide, calcium carbonate, calcium hydroxide, calcium sulfate, calcium chloride, dicalcium hydrogen phosphate, and calcium phosphate. Using the above-mentioned inorganic calcium compound as an inorganic carrier or one of the inorganic carriers results in a moderate binding force with the inorganic antibacterial component, and a moderate rate at which the inorganic antibacterial component detaches from the inorganic carrier—neither too fast nor too slow. Detachment that is too fast will not achieve a long-lasting antibacterial effect, while detachment that is too slow will release less inorganic antibacterial component, resulting in insufficient antibacterial activity.

[0037] In a preferred embodiment of the present invention, the inorganic carrier further comprises a second carrier, the second carrier accounting for no more than 30% of the weight of the inorganic carrier. The second carrier may be selected from one or a combination of two or more of zirconium phosphate, silica, zeolite, attapulgite, montmorillonite, bentonite, and kaolin. In addition to containing an inorganic calcium compound, the inorganic carrier of the present invention may also contain a second carrier. The second carrier has a better binding force with the inorganic antibacterial component; for example, the binding force between the inorganic antibacterial component and the inorganic calcium compound is higher, which inhibits the release rate of the inorganic antibacterial component. Therefore, the weight percentage of the second carrier in the inorganic carrier should not be too high, as a high percentage will affect the release rate of the inorganic antibacterial component, thereby affecting the antibacterial performance. Further preferably, the weight percentage of the second carrier in the inorganic carrier can be no less than 3%. For example, the weight percentage of the second carrier in the inorganic carrier can be any value from 3%, 5%, 7%, 9%, 10%, 12%, 14%, 15%, 17%, 20%, 22%, 23%, 25%, 27%, 28%, 30%, etc., but is not limited to those listed above. Adding a second carrier can inhibit the excessively rapid release of inorganic antibacterial components in the early stages, which is conducive to maintaining a more stable release of inorganic antibacterial components and improving the persistence of release.

[0038] In a preferred embodiment of the present invention, the antibacterial agent is prepared by mixing and dispersing an inorganic antibacterial component and an inorganic carrier. After mixing the inorganic antibacterial component and the inorganic carrier, the antibacterial agent can be obtained through high-speed dispersion or other methods. For example, the high-speed dispersion speed can be 1200-2000 rpm, and the dispersion time is not specifically limited, but can be 2-10 minutes.

[0039] On the other hand, the present invention provides a method for preparing an antibacterial ceramic material according to any of the above embodiments, comprising the following steps:

[0040] S1. Add the antibacterial agent to the glaze base material or ceramic base material, mix evenly, and obtain the premix;

[0041] S2. The premix from step S1 is coated onto the ceramic surface and sintered to obtain the antibacterial ceramic material of the present invention.

[0042] There are no particular restrictions on the glaze base material or ceramic base material in step S1 above. It can be a commercially available product, or it can be prepared with reference to the formula composition and preparation method in existing technologies such as CN116854373B, CN116282921B, CN116177985B, and CN115974411B.

[0043] In step S2 above, there is no particular limitation on the coating thickness of the premixed material on the ceramic surface. Taking the antibacterial outer layer as an example, the thickness of the antibacterial outer layer on the surface of the sintered antibacterial ceramic material can be 0.1-2mm, the sintering temperature can be 500-800℃, and the sintering time can be 1.5-3 hours.

[0044] The technical solution of the present invention will be further described and explained below with reference to various preparation examples and embodiments. Unless otherwise specified, the parts mentioned in the following embodiments are parts by weight.

[0045] Preparation Examples 1-10: Preparation of Antibacterial Agents

[0046] Preparation Example 1

[0047] The inorganic antibacterial component consists of silver phosphate and nano zinc oxide in a weight ratio of 1:15, with an average particle size of 45nm.

[0048] Mix 5 parts of inorganic antibacterial component and 95 parts of calcium carbonate (average particle size of 2 μm), and disperse at high speed of 1500 rpm for 5 min to obtain antibacterial agent.

[0049] Preparation Example 2

[0050] The difference between Preparation Example 2 and Preparation Example 1 is that in Preparation Example 1, the weight ratio of silver phosphate to nano zinc oxide was adjusted from 1:15 to 1:10. The remaining steps remained unchanged.

[0051] Preparation Example 3

[0052] The difference between Preparation Example 3 and Preparation Example 1 is that in Preparation Example 1, the weight ratio of silver phosphate to nano zinc oxide was adjusted from 1:15 to 1:4. The remaining steps remained unchanged.

[0053] Preparation Example 4

[0054] The difference between Preparation Example 4 and Preparation Example 3 is that in Preparation Example 3, the inorganic antibacterial agent was changed from 5 parts to 12 parts, and the calcium carbonate was changed from 95 parts to 88 parts. The remaining steps remained unchanged.

[0055] Preparation Example 5

[0056] The difference between Preparation Example 5 and Preparation Example 3 is that in Preparation Example 3, the inorganic antibacterial agent was changed from 5 parts to 20 parts, and the calcium carbonate was changed from 95 parts to 80 parts. The remaining steps remained unchanged.

[0057] Preparation Example 6

[0058] The difference between Preparation Example 6 and Preparation Example 3 is that in Preparation Example 3, all inorganic antibacterial components were replaced with silver phosphate. The remaining steps remained unchanged.

[0059] Preparation Example 7

[0060] The difference between Preparation Example 7 and Preparation Example 3 is that in Preparation Example 3, calcium carbonate was replaced with an equal weight of calcium sulfate (average particle size 2 μm). The remaining steps remained unchanged.

[0061] Preparation Example 8

[0062] The difference between Preparation Example 8 and Preparation Example 3 is that in Preparation Example 3, the calcium carbonate was adjusted to be an equal weight mixture of calcium carbonate and zirconium phosphate (average particle size 2 μm) in a weight ratio of 20:1. The remaining steps remained unchanged.

[0063] Preparation Example 9

[0064] The difference between Preparation Example 9 and Preparation Example 3 is that in Preparation Example 3, the calcium carbonate was adjusted to be an equal weight combination of calcium carbonate and zirconium phosphate (average particle size 2 μm) in a weight ratio of 3:1. The remaining steps remained unchanged.

[0065] Preparation Example 10

[0066] The difference between Preparation Example 10 and Preparation Example 3 is that in Preparation Example 3, the calcium carbonate was adjusted to be an equal weight combination of calcium carbonate and zeolite (average particle size 2 μm) in a weight ratio of 10:1. The remaining steps remained unchanged.

[0067] Comparative Preparation Example 1

[0068] The difference between Preparation Example 1 and Preparation Example 3 is that in Preparation Example 3, the calcium carbonate was replaced with an equal weight of zeolite (average particle size 2 μm). The remaining steps remained unchanged.

[0069] Comparative Preparation Example 2

[0070] The difference between Preparation Example 2 and Preparation Example 3 is that in Preparation Example 3, calcium carbonate was replaced with an equal weight of zirconium phosphate (average particle size 2 μm). The remaining steps remained unchanged.

[0071] Comparative preparation example 3

[0072] The difference between Preparation Example 3 and Preparation Example 4 is that in Preparation Example 3, the calcium carbonate was replaced with an equal weight of mesoporous silica (average particle size 2 μm). The remaining steps remained unchanged.

[0073] In Examples 1-12 and Comparative Examples 1-5 below, the composition of the glaze base material is as follows: 58 parts of potassium sodium feldspar, 14 parts of calcined talc, 14 parts of Suzhou clay, 3 parts of dolomite, 1.5 parts of zinc oxide, 0.5 parts of barium carbonate, 3 parts of zirconium silicate, and 3 parts of calcium phosphate.

[0074] Example 1

[0075] Take 100 parts of the above-mentioned glaze base material and put it into a ball mill. Add 90 parts of water and ball mill for 10 hours. Sieve the mixture and add 3 parts of the antibacterial agent of Preparation Example 3 to the obtained slurry. Stir at 1200 rpm for 20 minutes to obtain a premix.

[0076] The premixed material was coated on the surface of ceramic microspheres with an average diameter of 3 mm, dried, and sintered at 650℃ for 2 h to obtain antibacterial ceramic material with an average glaze thickness of 1 mm.

[0077] Example 2

[0078] The difference between Example 2 and Example 1 is that in Example 1, the antibacterial agent used in Preparation Example 3 was increased from 3 parts to 10 parts. The remaining steps remained unchanged.

[0079] Example 3

[0080] The difference between Example 3 and Example 1 is that in Example 1, the antibacterial agent used to prepare Example 3 was increased from 3 parts to 22 parts. The remaining steps remained unchanged.

[0081] Comparative Example 1

[0082] The difference between Comparative Example 1 and Example 1 is that in Example 1, the antibacterial agent used in Preparation Example 3 was increased from 3 parts to 30 parts. The remaining steps remained unchanged.

[0083] Example 4

[0084] The difference between Example 4 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Preparation Example 1. The remaining steps remained unchanged.

[0085] Example 5

[0086] The difference between Example 5 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Preparation Example 2. The remaining steps remained unchanged.

[0087] Example 6

[0088] The difference between Example 6 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Preparation Example 4. The remaining steps remained unchanged.

[0089] Example 7

[0090] The difference between Example 7 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Preparation Example 5. The remaining steps remained unchanged.

[0091] Example 8

[0092] The difference between Example 8 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Preparation Example 6. The remaining steps remained unchanged.

[0093] Example 9

[0094] The difference between Example 9 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Preparation Example 7. The remaining steps remained unchanged.

[0095] Example 10

[0096] The difference between Example 10 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Preparation Example 8. The remaining steps remained unchanged.

[0097] Example 11

[0098] The difference between Example 11 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Preparation Example 9. The remaining steps remained unchanged.

[0099] Example 12

[0100] The difference between Example 12 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Preparation Example 10. The remaining steps remained unchanged.

[0101] Comparative Example 2

[0102] The difference between Comparative Example 2 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Comparative Preparation Example 1. The remaining steps remained unchanged.

[0103] Comparative Example 3

[0104] The difference between Comparative Example 3 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Comparative Preparation Example 2. The remaining steps remained unchanged.

[0105] Comparative Example 4

[0106] The difference between Comparative Example 4 and Example 2 is that in Example 2, the antibacterial agent in Preparation Example 3 was replaced with an equal weight of the antibacterial agent in Comparative Preparation Example 3. The remaining steps remained unchanged.

[0107] Comparative Example 5

[0108] The difference between Comparative Example 5 and Example 2 is that in Example 2, the antibacterial agent used in Preparation Example 3 was replaced according to the composition and weight of silver phosphate and nano zinc oxide. That is, the antibacterial agent in this comparative example does not have a carrier and directly uses silver phosphate and nano zinc oxide. The remaining steps remain unchanged.

[0109] Antibacterial agent release test: Take 25g of the antibacterial ceramic material to be tested, soak it in 4L of water, soak for (n-1) days, pour out the solution, add another 4L of water and soak for one day, test the content of antibacterial agent in the solution at this time, which is the concentration of antibacterial agent ions released by the antibacterial ceramic material after soaking for n days.

[0110] Table 1 below shows the test results of the antibacterial ceramic material in Example 2.

[0111] Table 1

[0112] 1 0.158 0.742 120 0.051 0.405 7 0.119 0.555 150 0.046 0.388 14 0.078 0.421 180 0.049 0.361 21 0.080 0.479 210 0.041 0.256 30 0.062 0.482 240 0.035 0.248 60 0.050 0.511 300 0.026 0.184 90 0.055 0.549

[0113] As can be seen from the data in Table 1 above, the antibacterial ceramic material of the present invention has good antibacterial component release performance.

[0114] The solutions taken on days 60, 180, and 240 were tested for antibacterial activity against Staphylococcus aureus using the plate count method, and the results were 99.9%, 99.9%, and 98.5%, respectively.

[0115] Following the above-described method for testing antibacterial agent release, the release of antibacterial components was tested on the ceramic material under test at days 1, 60, 120, and 180. The results are shown in Table 2 below.

[0116] Table 2

[0117]

[0118]

[0119] As shown in Table 2 above, the antibacterial ceramic material of the present invention has good antibacterial sustained-release properties, and can continuously release antibacterial components to form a good antibacterial effect. Comparative Example 1 shows that adding too much antibacterial agent to the glaze greatly increases the cost, but the release rate of the antibacterial agent is too fast, resulting in poor continuous release and antibacterial effect. Using the plate count method to test the antibacterial rate of the solution against Staphylococcus aureus, the antibacterial rate of the solution after 120 days does not exceed 80%. Comparative Examples 2-5 show that using zeolite, zirconium phosphate, mesoporous silica, etc., as carriers for the antibacterial components makes the release of the antibacterial agent very difficult, resulting in a very low release amount and poor antibacterial effect. Using the plate count method to test the antibacterial rate of the solution against Staphylococcus aureus, the antibacterial rates of the solutions after 60 days and 120 days do not exceed 50% and 30%, respectively.

[0120] Example 13

[0121] The ceramic base material consists of 3 parts quartz sand, 8 parts potassium and sodium feldspar, 10 parts ball clay, 17 parts kaolin, 15 parts illite clay, 13 parts pyrophyllite, and 2 parts dolomite.

[0122] The above-mentioned ceramic base material was made into a slurry, which was then coated on the surface of a ceramic ball with a diameter of 1 cm. After drying, it was sintered at 1250℃ for 2 hours, and the thickness of the outer ceramic layer was 2 mm.

[0123] Example 14

[0124] The difference between Example 14 and Example 13 is that the antibacterial agent of Preparation Example 3 was added to the ceramic base material of Example 13, and the antibacterial agent accounted for 8% of the weight of the ceramic base material. The remaining steps remained unchanged.

[0125] The apparent porosity of the antibacterial ceramic materials in Examples 13 and 14 was tested according to GB / T 3810.3-2016 "Test Methods for Ceramic Tiles Part 3: Determination of Water Absorption, Apparent Porosity, Apparent Relative Density and Bulk Density". The apparent porosity of the ceramic material in Example 13 was 2.3%, and that in Example 14 was 3.7%. It is evident that adding an antibacterial agent to the outer layer of the ceramic material in this invention helps to increase the porosity of the ceramic material, thus facilitating the release of antibacterial components.

[0126] As described above, the basic principles, main features, and advantages of the present invention have been shown and described. Those skilled in the art should understand that the present invention is not limited to the above embodiments, which are merely preferred embodiments and should not be construed as limiting the scope of the invention. All equivalent changes and modifications made in accordance with the scope of the patent and the description should still fall within the scope of the present invention. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antibacterial ceramic material, characterized in that, The antibacterial ceramic material consists of a ceramic inner layer and an antibacterial outer layer; The antibacterial outer layer covers the outer surface of the ceramic inner layer, and the antibacterial outer layer contains an antibacterial agent; The antibacterial agent in the antibacterial outer layer shall not exceed 20% by weight and shall not be less than 3% by weight. The antibacterial agent is an inorganic antibacterial component loaded on an inorganic carrier; The inorganic antibacterial component is selected from one or more combinations of silver antibacterial agents and nano zinc oxide; The weight ratio of the inorganic antibacterial component to the inorganic carrier is 3-20:80-97; The inorganic carrier comprises an inorganic calcium compound, which is selected from one or more of calcium oxide, calcium carbonate, calcium hydroxide, calcium sulfate, calcium chloride, dicalcium hydrogen phosphate, and calcium phosphate. The inorganic carrier further includes a second carrier, wherein the weight percentage of the second carrier in the inorganic carrier is not higher than 30%. The second carrier is selected from one or more of zirconium phosphate, silica, zeolite, attapulgite, montmorillonite, bentonite and kaolin. The preparation method of the antibacterial ceramic material includes the following steps: S1. Add the antibacterial agent to the glaze base material or ceramic base material, mix evenly, and obtain a premix; S2. The premixed material described in step S1 is coated onto the ceramic surface and sintered to obtain the antibacterial ceramic material.

2. The method for preparing the antibacterial ceramic material according to claim 1, characterized in that, The silver antibacterial agent is selected from one or more of the following: silver nanoparticles, silver nitrate, silver nano oxide particles, silver sulfate, silver phosphate, and silver ammonium phosphate.

3. The method for preparing the antibacterial ceramic material according to claim 1, characterized in that, The inorganic antibacterial component is composed of silver antibacterial agent and nano zinc oxide in a weight ratio of 1:20-1:

1.

4. The method for preparing the antibacterial ceramic material according to claim 1, characterized in that, The antibacterial agent is prepared by mixing and dispersing the inorganic antibacterial component and the inorganic carrier.

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